The three-dimensional grain boundary network of sintered bulk strontium titanate is reconstructed using X-ray diffraction contrast tomography, a non-destructive technique for determining the grain shape and crystallographic orientation in polycrystals that is ideally suited for detailed studies of microstructure evolution. We present the first microstructure reconstruction of a perovskite comprising 849 grains and detailed interface orientation evaluations of individual grains. Comparison of structural and topological quantities to metallographic investigations and statistical grain models demonstrates the method’s validity and applicability.